AN EPIDEMIOLOGIC CASE-CONTROL ANALYSIS OF CHILDHOOD INTRACRANIAL AND SPINAL CORD TUMORS IN RELATION TO PATERNAL OCCUPATION AT BIRTH (BRAIN, CANCER)

Epidemiologic case-control studies of small groups of childhood nervous system tumor patients have suggested that parental employment in occupations with exposure to hydrocarbons is a risk factor for disease. The main focus of this case-control study was to assess the paternal occupation at the time of birth of offspring who later developed childhood intracranial and spinal tumors. All children under 15 years of age dying of such tumors in Texas, during the period 1964-1980, were selected as cases. Disease and demographic data were abstracted from death certificates. The birth certificate for each child of the final group of 499 cases was located and parental occupation information, as well as demographic and obstetric data, were collected. The comparison group consisted of a random sample from all Texas live births with the same birth year, race and sex distribution as the cases.^ The paternal occupations were categorized into broad classifications of those involving hydrocarbon exposure versus those that did not, based on the occupation criteria used in the previous studies. Odds ratios did not indicate any increased risk associated with general paternal hydrocarbon exposure in the workplace. In prior studies, increased risk estimates were detected with narrower groups of occupations involving exposure to hydrocarbon materials. The data from this study were classified according to these groups, and again, no increased risks were indicated except for a statistically insignificant but elevated odds ratio for fathers who were paper and pulp mill workers.^ Odds ratios were calculated for specific occupations and industries previously implicated as risk factors. Significantly associated odds ratios (OR) were detected for electricians (OR = 3.5), especially those working for construction companies (OR = 10.0), for employment in the printing occupations (OR = 4.5), particularly graphic arts workers (OR = 21.9), and in the electronics and electronic machinery industries (OR = 3.5). Analysis of the petroleum refining and chemical industries, which were not found in previous study populations, revealed significantly elevated odds ratios of 3.0 for occupations with probable heavy exposure to chemicals and petroleum compounds and 10.0 for salesmen of chemical products. ^

The Israelites found in the Anglo-Saxons : the ten tribes supposed to have been lost traced ... to their occupation of the isles of the sea ...

by William Carpenter

Loop formulation of supersymmetric Yang-Mills quantum mechanics

We derive the fermion loop formulation of N=4 supersymmetric SU(N) Yang-Mills quantum mechanics on the lattice. The loop formulation naturally separates the contributions to the partition function into its bosonic and fermionic parts with fixed fermion number and provides a way to control potential fermion sign problems arising in numerical simulations of the theory. Furthermore, we present a reduced fermion matrix determinant which allows the projection into the canonical sectors of the theory and hence constitutes an alternative approach to simulate the theory on the lattice.

Compactified N = 1 supersymmetric Yang-Mills theory on the lattice: continuity and the disappearance of the deconfinement transition

Fermion boundary conditions play a relevant role in revealing the confinement mechanism of N=1 supersymmetric Yang-Mills theory with one compactified space-time dimension. A deconfinement phase transition occurs for a sufficiently small compactification radius, equivalent to a high temperature in the thermal theory where antiperiodic fermion boundary conditions are applied. Periodic fermion boundary conditions, on the other hand, are related to the Witten index and confinement is expected to persist independently of the length of the compactified dimension. We study this aspect with lattice Monte Carlo simulations for different values of the fermion mass parameter that breaks supersymmetry softly. We find a deconfined region that shrinks when the fermion mass is lowered. Deconfinement takes place between two confined regions at large and small compactification radii, that would correspond to low and high temperatures in the thermal theory. At the smallest fermion masses we find no indication of a deconfinement transition. These results are a first signal for the predicted continuity in the compactification of supersymmetric Yang-Mills theory.

Numerical corrections to the strong coupling effective Polyakov-line action for finite T Yang-Mills theory

We consider a three-dimensional effective theory of Polyakov lines derived previously from lattice Yang-Mills theory and QCD by means of a resummed strong coupling expansion. The effective theory is useful for investigations of the phase structure, with a sign problem mild enough to allow simulations also at finite density. In this work we present a numerical method to determine improved values for the effective couplings directly from correlators of 4d Yang-Mills theory. For values of the gauge coupling up to the vicinity of the phase transition, the dominant short range effective coupling are well described by their corresponding strong coupling series. We provide numerical results also for the longer range interactions, Polyakov lines in higher representations as well as four-point interactions, and discuss the growing significance of non-local contributions as the lattice gets finer. Within this approach the critical Yang-Mills coupling β c is reproduced to better than one percent from a one-coupling effective theory on N τ = 4 lattices while up to five couplings are needed on N τ = 8 for the same accuracy.